Species boundary and phylogeographical pattern provide new insights into the management efforts of Megacopta cribraria (Hemiptera: Plataspidae), a bean bug invading North America

Integrative taxonomy, phylogenetics and historical biogeography of subgenus Aeschyntelus Stål, 1872 (Hemiptera: Heteroptera: Rhopalidae)

The subgenus Aeschyntelus includes six species that show variations in body color and shape, thus making it difficult to identify them based on morphological identification alone. To date, no genetic study has evaluated species within this genus. Herein, we collected 171 individuals from 90 localities of Rhopalus and employed an integrative taxonomic approach that incorporated morphological data, mitochondrial genomic data (COI, whole mitochondrial data) and nuclear genomic data (18S + 28S rRNAs, nuclear genome-wide SNPs) to delineate species boundaries. Our analyses confirmed the status of nine described species of Rhopalus and proposed the recognition of one new species known as Rhopalus qinlinganus sp. nov., which is classified within the subgenus Aeschyntelus. Discrepancies arising from nuclear and mitochondrial data suggest the presence of mito-nuclear discordance. Specifically, mitochondrial data indicated admixture within Clade A, comprising R. kerzhneri and R. latus, whereas genome-wide SNPs unambiguously identified two separate species, aligning with morphological classification. Conversely, mitochondrial data clearly distinguished Clade B- consisting of R. sapporensis into two lineages, whereas genome-wide SNPs unequivocally identified a single species. Our study also provides insights into the evolutionary history of Aeschyntelus, thus indicating that it likely originated in East Asia during the middle Miocene. The development of Aeschyntelus biodiversity in the southwestern mountains of China occurred via an uplift-driven diversification process. Our findings highlight the necessity of integrating both morphological and multiple molecular datasets for precise species identification, particularly when delineating closely related species. Additionally, it reveals the important role of mountain orogenesis on speciation within the southwestern mountains of China.

Mitogenomes Provide Insights into the Species Boundaries and Phylogenetic Relationships among Three Dolycoris Sloe Bugs (Hemiptera: Pentatomidae) from China

(1) Background: The three sloe bugs, Dolycoris baccarum, Dolycoris indicus, and Dolycoris penicillatus, are found in the Chinese mainland and are morphologically similar. The species boundaries and phylogenetic relationships of the three species remain uncertain; (2) Methods: In this study, we generated multiple mitochondrial genomes (mitogenomes) for each of the three species and conducted comparative mitogenomic analysis, species delimitation, and phylogenetic analysis based on these data; (3) Results: Mitogenomes of the three Dolycoris species are conserved in nucleotide composition, gene arrangement, and codon usage. All protein-coding genes (PCGs) were found to be under purifying selection, and the ND4 evolved at the fastest rate. Most species delimitation analyses based on the COI gene and the concatenated 13 PCGs retrieved three operational taxonomic units (OTUs), which corresponded well with the three Dolycoris species identified based on morphological characters. A clear-cut barcode gap was discovered between the interspecific and intraspecific genetic distances of the three Dolycoris species. Phylogenetic analyses strongly supported the monophyly of Dolycoris, with interspecific relationship inferred as (D. indicus + (D. baccarum + D. penicillatus)); (4) Conclusions: Our study provides the first insight into the species boundaries and phylogenetic relationships of the three Dolycoris species distributed across the Chinese mainland.

Limits of mitochondrial genes in delimiting species within a Carbula species complex (Hemiptera: Pentatomidae)

Molecular data has become a powerful tool for species delimitation, particularly among those that present limited morphological differences; while the mitochondrial genome, with its moderate length, low cost of sequencing and fast lineage sorting, has emerged as a practical data set. Due to the limited morphological differences among the closely related species of Carbula Stål 1865, the species boundaries between Carbula abbreviata (Motschulsky, 1866), Carbula humerigera (Uhler, 1860), and Carbula putoni (Jakovlev, 1876) have remained particularly unclear. In this study, we applied two phylogenetic reconstruction methods to two data sets (mitogenome and COI) to assess the phylogeny of Carbula distributed in Asia, and five species delimitation methods to determine the boundaries between East Asian Carbula species. Our phylogenetic analyses showed Carbula to be paraphyletic; the seven known species distributed within East Asia to form a single monophyletic group, and within this, C. abbreviata, C. humerigera, C. putoni and middle-type to comprise a C. humerigera species complex. Our results show that mitogenome data alone, while effective in the differentiation of more distantly related Carbula species, is not sufficient to accurately delimit the species within this newly described complex.

The complete mitochondrial genome of Aeschrocoristuberculatus and A.ceylonicus (Hemiptera, Pentatomidae) and its phylogenetic implications

Aeschrocoristuberculatus and A.ceylonicus (Hemiptera, Pentatomidae, Pentatominae) are mainly distributed in southern China, India, Myanmar, and Sri Lanka. Both species are also common agricultural pests. However, only the morphology of the genus Aeschrocoris has previously been studied, and molecular data have been lacking. In this study, the whole mitochondrial genomes of A.tuberculatus and A.ceylonicus are and annotated. The lengths of the complete mitochondrial genomes of the two species are 16,134 bp and 16,142 bp, respectively, and both contain 37 typical genes, including 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and a control region. The mitochondrial genome structure, gene order, nucleotide composition, and codon usage of A.tuberculatus and A.ceylonicus are consistent with those of typical Pentatomidae. Most PCGs of both species use ATN as the start codon, except atp8, nad1, and cox1, which use TTG as the start codon. cox1, cox2, and atp6 use a single T, and nad1 use TAG as the stop codon; the remaining PCGs have TAA as the stop codon. The A+T contents of the two species are 73.86% and 74.08%, respectively. All tRNAs have a typical cloverleaf structure, with the exception of trnS1, which lacks a dihydrouridine arm. The phylogenetic tree is reconstructed using the maximum-likelihood method based on the newly obtained mitochondrial genome sequences and 87 existing mitochondrial genomes of Pentatomoidea from the NCBI database and two species of Lygaeoidea as outgroups. The phylogenetic trees strongly support the following relationships: (Urostylididae + ((Acanthosomatidae + ((Cydnidae + (Dinidoridae + Tessaratomidae)) + (Scutelleridae + Plataspidae))) + Pentatomidae). This study enriches the mitochondrial genome database of Pentatomoidea and provides a reference for further phylogenetic studies.